380 



W. HAROLD LEIGH-SHARPE 



rectum, occupy the whole diameter to the exclusion of any 

 lumen. Their structure, appearance, and arrangement suggest 

 that of the mammalian kidney except that there are no mal- 

 pighian bodies and the blood supply is very slight. It is possible 

 that this organ is excretory in function and may get rid of poison- 

 ous substances not eliminated by the kidneys. 



pma. 



Fig. 15 Scyllium canicula. Transverse section of the rectal gland about its 

 middle, with a small inset of a single tubule of the gland under a high magnifica- 

 tion, p.m. a., posterior mesenteric artery; m., muscle; Gl., gland. 



ERRATUM 



Journal of Morphology, vol. 34, no. 2, September, 1920, Memoir I, page 

 256, figure 5, longitudinal should be transverse. The scale of this figure is in- 

 correct and should be 0.1, 0.3, 0.5 mm. 



